Back to back bathroom and stainless sink DWV layout

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New Member
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McRae, Arkansas
Please excuse the crudity of my diagram but I hope it helps illustrate what I am planning and what is hopefully correct.

The 3" vertical is the dry vent for my toilet, which extends out of my slab and will continue to the top of this framed room to an AAV (still inside the steel building)

I think the drain and venting is correct, the only thing I am unsure about is the 22-degree fitting in the 2" horizontal drain line. That is there to clear the 2" vertical pipe that I had originally planned to use as a greywater drain but have since decided just to plumb everything into my septic and use that 2" for something else. (thats the one with wire stuffed in it in the pic)

The bathroom sink will be stubbed out at 18" but on the outside of the bathroom but I have a stainless-steel sink I am installing that needs to be quite a bit lower around the 14" mark. Otherwise, I know it is common to use something like a back-to-back tee that services both sinks on both sides of the wall.

Any input is appreciated, thanks!


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Jeff H Young

In the Trades
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the 22s are no problem one santee pointed for lav other pointed for stainless sink at lower height is ok. so I think you're good , whether you can avoid the fittings is something you didn't ask and might be possible but a few 22s aren't hurting anything at all
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